Valveless pulse jet engine



y 6, 1953 J. 1.. STUART ,580

VALVELESS PULSE JET ENGINE Filed March 21, 1945 2 Sheets-Sheet l May 26, 1953 J. L. STUART 2,639,580

VALVELESS PULSE JET ENGINE Filed March 21, 1945 2 Sheets-Sheet 2 25 1/ FIG. 4

Attorney Patented May 26, 1953 umrru STATES rnreur tries VAL VELYESS PULSE JET ENGINE J amesLi Stuart, Sewickley, Pa.

Application March 21, 1945;, Serial No. 583,965

(01; fill- 35.6)

1 11 Claims. This invention relates to an improvement in the present known means and methods of generating and/ or using'kinetic energy-L A major object is to produce an exceedingly simple construction oi prime mover, motor or power-unit (hereinafter termed motor forbrevity-)- which embodies theinvention, so as to D- erate with greaterefiiciency at the expenditu ofmaterially less fueland which motor is canable of use without limitation in operating or propelling any object, mechanism or medium. 'A secondprimepbject is to provide such a motor as. will be devoid of .moving parts, such as valves, and whichmotor em loys one or more orifices. foradmitting air to" admin with fuel,

for cooling the motor and for internal thrust augmentation.

Other important aims are to provide such motor aforesaid wherein thefuel delivered is metered so that the permissible thrust obtained from its use may be variedwithin the motor, thefuelmay be activatedby a single initial explosion'and allexplosions are in such sequence as to effect a uniform or pulsatingfiow ofpower, and a construction. wherein increased efficiency is; attained=through the shape, dimensions and location of:baffle means ordefiectors in coaction with the fueland aircleliveries.

Qne. more desideratumis to provide such as motor which may have aform using asupplea.

mental shellfior-shells inthe combinationso arranged that gases which have. not been. eX-.

ploded: can be regenerated inthe original com.- bustion chamber or otherwise to produce opti+ mum. power, and which. shell on shells. shall:

also function in cooling thev motor.

'Still; furthen an aimis-to produce such motor utilizingnovel jet propulsion;

Various additional objects and-advantages willbecome apparent from aconsideration of the descriptionfollowing taken inv connection with accompanying drawings illustrating an, opera; tiveembodimentby Way of example, and which further, diagrammatically illustrate the jet propulsion operation and principles especially-withreierenceto its combustion cycle, to. enable. a more ready understandingof the present. inventiOn.

In said drawings Figure-1 isav-iew in central longitudinalsew.

Figure 3 isacross sevtional view takenon the li-ne s -tof Figure 2 and Figures 4- to 7 areviews diagrammaticall illustrating the combustion cycle of the motor of my invention.

Referring specifically to the drawings, and first to Figure 1 the motor a body or shell l'liprovided with a combustion chamber desig-, nated ll At the inlet end of the body. Iii it is, formedwith a closed chamber I2 constituting a tank or reservoir for liquid or other fuel which issupplied thereto through an inlet lit-leading from a source of supply carried by the body The fuel from the reservoir l2 isinjected into. the combustion chamber I! through any suitable number of nozzles it.

It will be noted that the outer wall of reservoir I2, is inturned or of tubular or tunnel shape. as. at It toprovide one or any desired numberrof. orifices [fifor the inlet of air into the comlcuis-v tionchamber I l' for admixture with fuel therein. andfor cooling purposes. The fuel-nurturev in. combustionchamber i! is adapted to be ignited once by any suitable means, electrical, mechans ical or otherwise its-suggested at H, the exhaust. leaving the body it at Iii. Thus it will be seen that the improved motor according to my. in.- vention is devoid of any valves, and that in lieu thereof, I use one or any desired number 'of permanently open orifices such as IE3. As a result of this construction, the motor it} accordin to my invention willrernain operative under any load of fuelsupply it is capable of carrying, and. the life of the motor will not be aifected or shortened by the presence ofvalves and particularlyrthe"burning out? thereof.

Asecond or modified form of my invention is disclosed in Figures 2 and 3. In this form, a body shell or casing It is used corresponding to that at lll with the exception that the inlet endor encl opposite to the exhaust is open as shown. Theignition or firing means llf corre; spondsto that used at H.

Body orflshell. It is located axially within. a largerv and longer shell ldwhich is open at both. ends and which generally conforms in shape thereto and projects outwardly beyond both ends thereof.

Also disposed axially of the shell 19 and in alinementwith the body Ill, forwardly thereof, is. alhollow body generally designated 2!]. This body 25% and the body It are connected-to the shell by means of any suitable number of preferably equidistantly spaced struts or webs 2! and; 2-; on ud na l J t O QiI shape insection.

' directions.

The hollow body 20 constitutes a fuel reservoir to which fuel is supplied through a conduit 13 similar to that at l3 from a source of fuel supply which is carried by the shell IS in the same man ner that the fuel supply is carried by body [8. Centrally, body 20 is of funnel shape having a tube 23 for the inlet of air into the combustion chamber ll of the motor l and fuel from the hollow chamber is supplied to the combustion chamber II in any suitable manner as through one or more nozzles 24 mounted in the wall of tube 23 and communicating with the interior of chamber 20 and the bore of said tube. While I have shown only one tube 23 constituting an orifice, it is to be understood that I may use any desired number of such tubes or otherwise provide a multiplicity of orifices to supply air or air and liquid fuel to the combustion chamber H.

It will be noted that the inner transverse wall of body 20 is spaced from the open end of combustion chamber II and also extends latrally beyond such end, to serve as a baifle means or deflector means. This wall 25 is preferably generally cupped shape as shown in that from a fiat base it convexly curves to the margin, at 25. It will be noted that the discharge end of the shell l9, designated 26, projects beyond the discharge end [8 of the motor [0.

This form of Figures 2 and 3 is devoid of valves for'the intake of air and for the latter purpose. has one or a plurality of permanently open orifices such as 23 or the equivalent. The shell I9 provides a second air chamber 2? around the body or motor ID for the purpose of thrust augmentation and/or for a second combustion chamber, for which purpose, it may have an ignitor Ila like that at H and IT or any equivalent. The beginning of each of these cycles is synchronized by means of the position of the outer shell [9 with reference to the inner shell or body of the motor [0' and by varying the depth and shape of the tube or orifice 23 and baflle means or deflector surface 25. The chamber 21 also acts as an economizer of fuel as well as serving as a cooling jacket for the inner shell of the motor in.

Figures 4 to 7 illustrate the combustion cycle of the motor shown in Figure 2 of the patent drawing, but it is to be understood that the same operation is true for the corresponding parts employed in Fig. l, the main difference being the non-employment of tube or shell l9 and functions thereof. The combustion chamber is in the tubes Hi and I0 and in Fig. 2 the outer tube or shell I9 is used as an air chamber and thrust augmenter. The hot and burned gases of the cycle under consideration are illustrated by dot stippling and the burned gases of the previous cycle by x stippling. Said Figure 4 illustrates a combustion moment very shortly after the ignition of the gas mixture in combustion chamber 1 I. While the flame front moves to the left into the region of the unburned gases a violent expansion of the compressed burned gases toward the exhaust takes place. In Figure 5, the flame front has entered the inlet tube 23 filled with the gax mixture, leaving in the combustion tube or shell 10' burned gases expanding now in both The flame front in Figure 6 has reached the open end of the inlet tube 23 followed by a small part of the combustion gas. Some of the combustion gas escapes into the open air and some is thrown back int-o the air chamber I9 by the wind pressure and contributes to the propulsive efiiciency of the motor. The other or far greater part of the combustion gases leaves the combustion tube or shell I0 through both ends of it entering the space of the outer shell and moves partly mixed with air, toward the exhaust of the outer tube or shell [9. The thrust of the motor is determined by the difference in momentum of gases leaving and entering the open ends of the outer tube or shell [9. In Figure '7, the combustion gases are shown moving out of the inner tube or shell 10' leaving behind them a region of low pressure which, in turn, permits the air outside to move into the inlet tube 23 and, mixed with fuel, enter the combustion chamber l I. At the same time the remnants of hot gases inside the inner tube or shell l0 close to the exhaust end, will reverse their motion and meet the fresh charge in combustion chamber H when another ignition occurs and starts a new combustion cycle.

Various changes may be resorted to provided they fall within the spirit and scope of the invention.

What is claimed is:

1. A jet propulsion motor including tube-like structure having an inlet end, an open outlet end, and a combustion chamber therebetween, a fuel reservoir disposed at said inlet end, said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to said reservoir, said reservoir having a wall disposed transverse-"1y with respect to said combustion chamber in position to directly receive the impact of shock waves for rearward deflection, said reservoir having air inlet conduit means providing an orifice through said reservoir with one extremity through said wall in direct communication with the combustion chamber and open to the atmosphere at the other extremity, injector nozzle means for passage of fuel from the reservoir into the line of air passage to the combustion chamber, and fuel ignition means in said combustion chamber.

2. A jet propulsion motor including tube-like structurehaving an inlet end, an open outlet end, and a combustion chamber therebetween, a fuel reservoir at said inlet end, said reservoir having a wall disposed transversely with respect to said combustion chamber in position to directly receive the impact of shock waves for rearward defiection, said reservoir having air inlet conduit means providing an orifice through said reser voir with one extremity through said wall in direct communication with the combustion chamher and open to the atmosphere at the other extremity, injector nozzle means for passage of fuel from the reservoir into the line of air passage to the combustion chamber, and fuel ignition means in said combustion chamber.

3. A. jet propulsion motor including tube-like structure having an inlet end, an open outlet end, and a combustion chamber therebetween, said combustion chamber having a main portion and a rear portion progressively decreasing in crosssection toward said outlet end, a fuel reservoir disposed at said inlet end said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to said reservoir, said reservoir having a wall disposed transversely with respect to said combustion chamber in position to directly receive the impact of shock waves for rearward deflection, said reservoir having air inlet conduit means providing a permanently open valveless orifice through said reservoir with one extremity through said wall in direetsi'communlcatibnawith;,thewombustionrchamber-valid: open to-the=,-atmosphere at the= other extremity; injection nozzle means for passageoffuel fr'om the reservoir"into the -line of 'air passage:to' the combustion chamber; and' fuel igni tion means insaid main portionof=-the combus- I tion-chamber;

4: A jet propulsion motor includingatubular: body having -an -inlet' end, an open outlet: end and atcombustion chamber 'therebetween, a fuelreservoir .at said-inletend having a wall arranged across said body; saidbody'at -said inlet end=out wardly-:of said wall havingan inturnedfunnel,

wall structure extending from the outer .portionof sa-id -fu-nnel inwardly to said "wall cooperating with the latter and said funnelto form said reservoir, said funnel providing an orifice through said reservoir-:- with its inner extremity opening through said inner walland thereby communicating with the combustion chamber, said "orifice being opemto;utheeatmosphereaatisaidaouter portion, nozzle means for projection of fuel fromthe:

reservoirjn-to the line of air passage to the come bustionchamber, saidcombustion chamber have ingea portion and a-,-.rear. portion progressi-vely decreasing in cross-section toward said outlet end, and. fuel ignition means in said main portion of the combustion chamber.

5. A jet propulsion-motor comprising an elongateditubular structurenproviding a combustion chamber as; part of a1.continuousi space 1 therethrough constantly 0133213 130; the atmosphere at both:ends ,,afuel reservoir carried by said structure having, an wall disposed transverselyv of said combustionchamber in position'to directlyrreceive the impact of shock waves for rearward deflection, means to supply fuel to said reservoir, nozzle means from the reservoir for injection of fuel from the reservoir into the line of air passage to the combustion chamber, and fuel ignition means in said combustion chamber.

6. A jet propulsion motor comprising an elongated tubular structure providing a combustion chamber as part of a continuous space therethrough constantly open to the atmosphere at both ends, a fuel reservoir carried by said structure, means to supply fuel to said reservoir, nozzle means from the reservoir for injection of fuel from the reservoir into the line of air passage to the combustion chamber, fuel ignition means in said combustion chamber, and a shell surrounding and mounting said tubular structure enlarged with respect to the latter to define an air chamber for thrust augmentation, said air chamber being in communication with the combustion chamber and open to the atmosphere at both end of said tubular structure and means adjacent the inlet end of the combustion chamber for impact by shock waves therefrom shaped to deflect the shock waves therefrom through said air chamber in the direction of the outlet of said air chamber.

'7. A jet propulsion motor including tube-like structure having an inlet end, an open outlet end, and a combustion chamber therebetween, a fuel reservoir disposed at said inlet end, said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to said reservoir, said reservoir having air inlet conduit means providing an orifice through said reser voir with one extremity in communication with the combustion chamber and open to the atmosphere at the other extremity, injector nozzle means for passage of fuel from the reservoir into the line of air passage to the combustion chamher;- fuelJignition means in said-combustion chamber,- a shell mounting and surrounding:said tube like: structuretenlargedlwith respect to the latter to-provide an air chamber for thrust augmentation, said" latter: chamber being-in communicationzwith the-inlet: of the combustion chamber and open tothe atmosphereatboth ends of said tube-like structure and means adjacent the inlet end" of" the combustion. chamber forimpact by shock waves therefrom. shaped to deflect the shock-:wavestherefroln through said air cham-. bore inthe; direction of the outlet of said air chamber.

83 A: jet.- propulsion motor including tube-like strueture having aninletend; an open'outlet end;

and iaacombustion chamber therebetween, a fuel reservoir disposed at" said inlet end, said fuel reservoir being annular transversely with a respect to saidistruoture, means to supply fuel to said.

reservoir, said reservoir having air inlet. conduit means-providing. an orifice through said reservoir "with one extremity in communication withthe combustion. chamber andopen to the atmos-..

phere at the other extremity, injector nozzle means forpassage of fuel from the reservoir into.

the line of air passage tothe combustion chamber, fuel ig-nitionmeansin saidcornbustion cham-. ber, a shell mounting and surroundingsaid-tube likestructure enlarged with respect to the latter to providean air chamber-for thrust-augmenta-.

tion, saidlatter chamberbeingin communicashock waves therefrom through said air chamber in the direction of the outlet of said air chamber, and ignition means in said air chamber.

9. A tube-like jet propulsion motor structure comprising a tube member open at opposite ends and a fuel reservoir disposed in front of said tube member, said tube member forming a combustion chamber and being open at its inlet and outlet ends, a shell open at both ends to the atmosphere surrounding said tube member enlarged with respect to the latter to provide an air chamber for thrust augmentation, said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to the reservoir, said reservoir having a tube providing an orifice through said reservoir with one extremity in communication with said combustion chamber and open to the atmosphere at the other extremity, injection nozzle means for passage of fuel. from the reservoir through said tube into said combustion chamber, fuel ignition means in said combustion chamber, said reservoir having a wall through which said tube extends disposed in spaced relation to the front of said tube member to provide communication between the tube member and air chamber, said wall having a shape to form a shock wave bafile to deflect the shock waves therefrom through said air chamber in the direction of the outlet of said air chamber.

10. A tube-like jet propulsion motor structure comprising a tube member open at opposite ends and a fuel reservoir disposed in front of said tube member, said. tube member forming a combustion chamber and being open at its inlet and outlet ends, a shell open at both ends to the atmosphere surrounding said tube member enlarged with respect to the latter to provide an air chamher for thrust augmentation, said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to the reservoir, said reservoir havinga tube providing an orifice through said reservoir with one extremity in communication with said combustion chamber and open to the atmosphere at the other extremity, injection nozzle means for passage of fuel from the reservoir through said tube into said combustion chamber, fuel ignition means in said combustion chamber, said reservoir having a wall through which said tube extends disposed in spaced relation to the front of said tube member to provide communication between the tube member and air chamber, said wall being laterally enlarged and cupped with respect to the front of said tube member to form a shock wave bafileto deflect the shock waves therefrom through the said air" chamber in the direction of the outlet of said air chamber.

11. A tube-like jet propulsion motor including a structure comprising a tube member open at opposite ends and a fuel reservoir disposed in front of said tube member, said tube member forming a combustionchamber and being open at its inlet and outlet "ends, a shell open at both ends to the atmosphere surrounding said tube member enlarged with respect to the latter to provide an air chamber for thrust augmentation,

said fuel reservoir being annular transversely with respect to said structure, means to supply fuel to the reservoir, said reservoir having a tube providing an orifice through said reservoir with one extremity in communication with said combustion chamber, and open to the atmosphere at the other extremity, injection nozzle means for 8 passage of fuel from the reservoir through said tube into said combustion chamber, fuel ignition means in said combustion chamber, said reservoir having a wall through which said tube ex tends disposed in spaced relation to the front of said tube member to provide communication between the tube member and air chamber, said wall having a shape to form a shock wave baflle to deflect the shock waves therefrom through said air chamber in the direction of the outlet of JAMES L. STUART.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,329,559 Tesla Feb. 3, 1920 1,369,672 Koenig Feb. 22, 1921 1,852,164 Holzwarth Apr. 5, 1932 2,195,025 Couzinet Mar. 26, 1940 2,335,005 Gieskieng et a1 Nov. 23, 1943 FOREIGN PATENTS Number Country Date 293,594 Great Britain Aug. 16, 1928 439,805 Great Britain Dec. 6, 1935 412,478 France May 3, 1910 530,327 France Sept. 30, 1921 Austria Jan. 26, 1914 

